This invention relates generally to storage networking semiconductors and in particular to a high performance network storage processor that is used to create Internet Protocol (IP) based storage networks.
Internet protocol (IP) is the most prevalent networking protocol deployed across various networks like local area networks (LANs), metro area networks (MANs) and wide area networks (WANs). Storage area networks (SANs) are predominantly based on Fibre Channel (FC) technology. There is a need to create IP based storage networks.
When transporting block storage traffic on IP designed to transport data streams, the data streams are transported using Transmission Control Protocol (TCP) that is layered to run on top of IP. TCP/IP is a reliable connection/session oriented protocol implemented in software within the operating systems. TCP/IP software stack is very slow to handle the high line rates that will be deployed in future. Currently, a 1 GHz processor based server running TCP/IP stack, with a 1 Gbps network connection, would use 50-70% or more of the processor cycles, leaving minimal cycles available for the processor to allocate to the applications that run on the server. This overhead is not tolerable when transporting storage data over TCP/IP as well as for high performance IP networks. Hence, new hardware solutions would accelerate the TCP/IP stack to carry storage and network data traffic and be competitive to FC based solutions. In addition to the TCP protocol other protocols such as SCTP and UDP protocols can be used, as well as other protocols appropriate for transporting data streams.